How Do Rapid-Acting Insulins Work?

Rapid-acting insulins are a class of drugs used to control high blood sugar in people with type 1 (T1DM) and type 2 diabetes mellitus (T2DM) along with a proper diet and exercise. T1DM or insulin-dependent diabetes is an autoimmune condition in which the body does not produce insulin and therefore cannot control the amount of sugar in the blood. However, T2DM is a slowly progressive metabolic disorder caused by a combination of genetic and lifestyle factors that promote chronically elevated blood sugar levels. Rapid-acting insulins work very quickly to minimize the rise in blood sugar after eating and their effects last for a couple of hours. This type of insulin is often used with longer-acting insulin for maintaining blood glucose for a longer period.

Insulin is a peptide hormone produced by the beta cells of the pancreas to help metabolize food and use it for energy throughout the body. After a meal, insulin promotes the uptake of glucose (a type of sugar found in many carbohydrates) from the blood into internal organs and tissues such as the liver, fat cells, and skeletal muscles. It allows the body to use glucose for energy; helps in the storage of glucose in the liver, fat, and muscles; and regulates the body’s metabolism of carbohydrates, fats, and proteins.

Rapid-acting insulins are administered as a solution (liquid), a suspension (liquid with particles that will settle on standing) to be injected subcutaneously (under the skin) typically within 15 minutes before a meal, and a powder to be orally inhaled using a special inhaler.

Rapid-acting insulins work in the following ways:

• They are short-acting man-made products similar to human insulin. 
• They act faster than soluble insulin and are therefore extremely useful around mealtimes.
• They work by replacing the insulin that is normally produced by the body and by helping sugar movement from the blood into other body tissues where it is used for energy.
• In addition, they inhibit the liver from producing more sugar.

Rapid-acting insulins are indicated to improve glycemic control in patients with T1DM and T2DM along with a proper diet and exercise.

Some of the common side effects include:

• Injection site reaction (pain, redness, and irritation)
• Weakness
• Diarrhea
• Headache
• Tiredness
• Nausea
• Cough
• Sore throat
• Asthenia (abnormal physical weakness or lack of energy)
• Back pain

Other rare side effects include:

• Weight gain
• Hypokalemia (low blood potassium level)
• Muscle cramps
• Dizziness (feeling faint, weak, or unsteady)
• Swelling of the arms, hands, feet, ankles, or lower legs
• Shortness of breath
• Upper respiratory infection
• Nasopharyngitis (an inflammatory attack of the pharynx and nasal cavities)
• Confusion
• Lipodystrophy (a problem with the way the body uses and stores fat)
• Hypoglycemia (low blood sugar level)
  • Sudden sweating
  • Fast heartbeat
  • Blurred vision
  • Tingling in hands/feet

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of rapid-acting insulins include:

• Admelog
• Admelog solostar
• Afrezza
• Apidra
• Apidra solostar
• Fiasp
• Humalog
• Humalog junior kwikpen
• Humalog kwikpen
• Insulin aspart
• Insulin glulisine
• Insulin inhaled
• Insulin lispro
• Insulin lispro-aabc
• Lyumjev
• NovoLog
• NovoLog FlexPen
• NovoLog FlexTouch
• NovoPen Echo